Hebei Messi Biology Co., Ltd. stated that it used homemade and commercially available magnesium hydroxide slurries to conduct neutralization treatment experiments on steel mill pickling wastewater, mainly comparing turbidity, chroma, CODcr, hexavalent chromium (Cr(VI)) and suspended solids content SS removal rate. The results showed that the treatment effects of homemade and commercial slurries were equivalent, with turbidity removal rates of 86.3% and 87.3% respectively, chroma removal rates of 88.4% and CODcr removal rates of 44.5% and 48.5% respectively, Cr(VI) removal rates of 100% and SS removal rates of 88.o%, and the treated water quality met the industrial wastewater discharge standards.
A method for preparing ultrafine magnesium hydroxide slurry by wet method, comprising the following steps:
Step 1. First, add 1-10 parts by weight of a high-efficiency surfactant and 10-30 parts by weight of a grinding aid to 70-700 parts by weight of water, disperse them uniformly and set aside; Step 2. Then weigh 50-150 parts by weight of magnesium hydroxide powder and add it to the standby solution of step 1, disperse and prepare a magnesium hydroxide suspension to be ground; Step 3. Add 400-600 parts by weight of grinding medium balls to the magnesium hydroxide suspension to be ground in step 2, and grind to an ultrafine magnesium hydroxide slurry of target particle size; Step 4. Add 0.1-5 parts by weight of a composite stabilizing agent to the ultrafine magnesium hydroxide slurry in step 3; The method of the present invention is beneficial to environmental protection, has low production cost, and can improve the stability of magnesium hydroxide slurry under the premise of unchanged high solid content.